Electromagnetic wave antennas, and radio frequency (RF) antennas in particular, are widely used to transmit and receive energy in the form of radio waves. RF antennas are available in many different shapes, sizes and configurations. One type of RF antenna is the Cassegrain antenna. Cassegrain antennas have a hyperbolic shaped sub-reflector. The sub-reflector is coaxially aligned with and aimed at an axial center of a main parabolic reflector. The sub-reflector Is suspended above the main reflector by either a solid support tube extending from a point near the center of the main reflector, one or more support rods extending from a point near the center of the reflector, or one or more support rods extending from a periphery of the main reflector. When the antenna is in the receive mode the sub-reflector directs RF energy received and reflected by the main reflector to a waveguide (i.e., feedhorn) located at the axial center of the main reflector. When the antenna is in the transmit mode, RF energy transmitted from the waveguide is reflected by the sub-reflector onto the main reflector where the energy is radisted from the antenna.
While the above described Cassegrain antenna is able to adequately send and receive radio signals, it would be desirable to improve its operating efficiency. Specifically, Cassegrain antennas and all other types of antennas which employ the use of a device suspended above a main reflector, such as a horn antenna, patch antenna, etc., suffer transmission losses due to the RF signal being blocked and reflected by the device support members. Such support members are usually in the form of solid support tubes or support rods that exhibit large dielectric constants. Consequently, there is a need for an improved antenna exhibiting reduced levels of reflection loss and dielectric loss, resulting in enhanced RF signal transmission and reception.